Outline

Objective: Extratemporal epilepsies remain a challenge both with respect to presurgical evaluation and surgical treatment since the epileptogenic area is frequently diffuse and overlaps eloquent areas. Therefore, extratemporal epilepsies usually require extensive presurgical work-up including invasive recordings. Here, we provide an overview on our experience with a total of 253 procedures in 236 patients.

Methods: Between 1998 and 2010 a total of 236 patients received 253 therapeutic procedures. Histopathological specimen were available in 226 patients. Epileptological follow-up of at least 1 year (range from 3 to 120 months) was obtained in 158 patients. In 75 patients (32%), invasive mapping with subdural and/or depth electrodes was performed prior to surgery.

Results: The majority of resections concerned the frontal lobe (55.9%; parietal: 6.2%, occipital: 8.2%). Multilobectomy involving 2 lobes was performed in 16.4% and involving 3 lobes in 5.6% of the cases. Histopathological examination revealed focal cortical dysplasia in 48.9%, other non-neoplastic lesions in 26.9% and neoplastic lesions in 24.2% of the specimen. During a mean follow-up of 36 months, 97 (61.4%) of the patients remained seizure-free, 38 (24%) had a significant seizure reduction of > 75%. Operative complications were temporary in 38 cases (20%) and permanent in 4 cases (2.1%). There was no operative mortality.